#include <bits/stdc++.h>

using namespace std;
const int N = 1010;
int f[N], a[N];
int n;
int main()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        f[i] = a[i];
    }
    for (int i = 2; i <= n; ++i)
    {
        for (int j = 1; j < i; ++j)
        {
            if (a[j] < a[i])
            {
                f[i] = max(f[i], f[j] + a[i]);
            }
        }
    }
    int ret = 0;
    for (int i = 1; i <= n; ++i)
    {
        ret = max(ret, f[i]);
    }
    cout << ret;
    return 0;
}